Proper catheterization: Size, duration, and patient physiology

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Theresa Cosper-Roberts, RVT, CVPM, ACE(DE), CVBL, is a distinguished expert of the Academy of Veterinary Educators with more than 10 years of experience in veterinary education. She is also the surgical training center manager at the Louisiana State University (LSU) School of Veterinary Medicine, as well as the senior consultant for National Veterinary Solutions, LLC, which specializes in providing tailored consultations and training for veterinary technicians, students, and assistants. In her role at the LSU School of Veterinary Medicine, she has been placed on the dean’s merit honor roll as an instructor each year, making her the first veterinary technician to achieve this accolade.

In an interview with dvm360, Cosper-Roberts talked about her lecture Is Bigger Always Better? Intravenous Catheterization of Companion Animals, presented at the Southwest Veterinary Symposium in Fort Worth, Texas. In the interview, Cosper-Roberts discussed the process of choosing the right catheter size and the duration a catheter can, and should, be in place. She also explained the role a patient’s physiology plays in the decision.

Learn more in this Q&A style interview:

How should veterinary technicians and assistants choose the right catheter for their patients? What factors should be considered?

“So, the old school thing that we always taught people is ‘bigger is better: get the biggest catheter that you can possibly get in that patient, because you never know if something's going to happen or [if] that patient [is going to] code.’ But that isn't necessarily the case. Yes, we want to choose a large catheter, but it needs to be the biggest catheter that is appropriate for that patient.

I always tell my students, just because I can get an 18-gage catheter in a cat doesn't mean that it's appropriate for that cat to have an 18-gage catheter. So, it's looking at the patient as a whole, and what's going on with that patient, what they're there for, how long that catheter is going to be in dwelling, in order to decide what the best catheter [is] for that patient.”

What role does a patient's physiology play in the type of catheter that should be used?

“Patient physiology has a very, very important role. When we're looking at a Dachshund, I know that if I'm going to put a catheter in a Dachshund, that I probably need a short catheter, because I'm not going to be able to place a 2-inch catheter in most of their legs. If I'm placing a catheter in a Great Dane or a very large breed, I'm probably reaching for a 14- or 16-gage catheter because they're a larger patient who can accommodate a larger size.

Depending on what that animal is there for, instead of doing a peripheral catheter if that animal is going to be hospitalized for a while, or if it's fairly critical, I may place a central line or a midline. So, it truly is looking at the patient as a whole and everything that's going on with that patient to try and decide the best catheter for them.”

How long should catheters be kept in place? How is that determined?

“So, there are 2 schools of thought with that, there's what I refer to as ‘old school’ or ‘new school.’ And ‘old school’ school of thought is 72 hours max it gets pulled because after that there's a risk of infection.

But the CDC recommendations are actually that as long as a patient isn't showing any signs of a catheter site infection or any issues associated with that limb, that catheters can remain indwelling. So, if we're not feeling any heat at the limb, if the animal isn't showing any signs of pain or swelling or from phlebitis or anything like that, that catheter can stay in, because what we don't want to do is pull a perfectly good catheter that doesn't have anything wrong with it because we're getting stuck in ‘Okay, this is the rule. This is what I need to do,’ because every time I poke a dog, I'm risking introducing something into that patient. So we want to minimize the amount of times that we are poking our patients, if we need [to] be.”